1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 68e121eeccbc..047f6f6ed3f6 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -877,6 +877,27 @@ static int emulator_read_emulated(unsigned long addr,
         }
 }
 
+static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
+                               unsigned long val, int bytes)
+{
+        struct kvm_memory_slot *m;
+        struct page *page;
+        void *virt;
+
+        if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
+                return 0;
+        m = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT);
+        if (!m)
+                return 0;
+        page = gfn_to_page(m, gpa >> PAGE_SHIFT);
+        kvm_mmu_pre_write(vcpu, gpa, bytes);
+        virt = kmap_atomic(page, KM_USER0);
+        memcpy(virt + offset_in_page(gpa), &val, bytes);
+        kunmap_atomic(virt, KM_USER0);
+        kvm_mmu_post_write(vcpu, gpa, bytes);
+        return 1;
+}
+
 static int emulator_write_emulated(unsigned long addr,
                                    unsigned long val,
                                    unsigned int bytes,
@@ -888,6 +909,9 @@ static int emulator_write_emulated(unsigned long addr,
         if (gpa == UNMAPPED_GVA)
                 return X86EMUL_PROPAGATE_FAULT;
 
+        if (emulator_write_phys(vcpu, gpa, val, bytes))
+                return X86EMUL_CONTINUE;
+
         vcpu->mmio_needed = 1;
         vcpu->mmio_phys_addr = gpa;
         vcpu->mmio_size = bytes;